Benjamı́n Béjar

ORCID: 0000-0001-9705-4483
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About
Contact & Profiles
Research Areas
  • COVID-19, Geopolitics, Technology, Migration
  • Regional Socio-Economic Development Trends
  • Impact of AI and Big Data on Business and Society
  • Sparse and Compressive Sensing Techniques
  • Human Pose and Action Recognition
  • Energy Efficient Wireless Sensor Networks
  • Cooperative Communication and Network Coding
  • Multimodal Machine Learning Applications
  • Indoor and Outdoor Localization Technologies
  • COVID-19 epidemiological studies
  • Distributed Control Multi-Agent Systems
  • Advanced MIMO Systems Optimization
  • Target Tracking and Data Fusion in Sensor Networks
  • Advanced Wireless Communication Techniques
  • Hand Gesture Recognition Systems
  • Distributed Sensor Networks and Detection Algorithms
  • Data-Driven Disease Surveillance
  • Video Analysis and Summarization
  • Blind Source Separation Techniques
  • Human Motion and Animation
  • Wireless Communication Security Techniques
  • Underwater Vehicles and Communication Systems
  • Autism Spectrum Disorder Research
  • Photoacoustic and Ultrasonic Imaging
  • Millimeter-Wave Propagation and Modeling

Swiss Data Science Center
2020-2025

Paul Scherrer Institute
2022-2025

École Polytechnique Fédérale de Lausanne
2013-2023

ETH Zurich
2021-2022

Johns Hopkins University
2011-2020

Institute of Electrical and Electronics Engineers
2018

Signal Processing (United States)
2018

École Normale Supérieure - PSL
2014

Universidad Politécnica de Madrid
2007-2012

European Telecommunications Standards Institute
2008

<italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">Objective</i> : State-of-the-art techniques for surgical data analysis report promising results automated skill assessment and action recognition. The contributions of many these techniques, however, are limited to study-specific validation metrics, making progress across the field extremely challenging. xmlns:xlink="http://www.w3.org/1999/xlink">Methods</i> In this paper, we address two major...

10.1109/tbme.2016.2647680 article EN publisher-specific-oa IEEE Transactions on Biomedical Engineering 2017-01-04
Katharine Sherratt Hugo Gruson Rok Grah Helen Johnson Rene Niehus and 95 more Bastian Prasse Frank Sandmann Jannik Deuschel Daniel Wolffram Sam Abbott Alexander Ullrich Graham Gibson Evan L Ray Nicholas G Reich Daniel Sheldon Yijin Wang Nutcha Wattanachit Lijing Wang Ján Trnka Guillaume Obozinski Tao Sun Dorina Thanou Loïc Pottier Ekaterina Krymova Jan H. Meinke Maria Vittoria Barbarossa Neele Leithäuser Jan Möhring Johanna Schneider Jarosław Wlazło Jan Fuhrmann Berit Lange Isti Rodiah Prasith Baccam Heidi Gurung Steven Stage Bradley Suchoski Jozef Budzinski Robert Walraven Inmaculada Villanueva Vít Tuček Martin Šmíd Milan Zajíček Cesar Perez Alvarez Borja Reina Nikos I Bosse Sophie Meakin Lauren Castro Geoffrey Fairchild Isaac Michaud Dave Osthus Pierfrancesco Alaimo Di Loro Antonello Maruotti Veronika Eclerová Andrea Kraus David Kraus Lenka Přibylová Bertsimas Dimitris Michael Lingzhi Li Soni Saksham Jonas Dehning Sebastian Mohr Viola Priesemann Grzegorz Redlarski Benjamı́n Béjar Giovanni Ardenghi Nicola Parolini Giovanni Ziarelli Wolfgang Böck Stefan Heyder Thomas Hotz David E Singh Miguel Guzmán-Merino Jose L Aznarte David Moriña Sergio Alonso Enric Àlvarez Daniel López Clara Prats Jan Pablo Burgard Arne Rodloff Tom Zimmermann Alexander Kuhlmann Janez Žibert Fulvia Pennoni Fabio Divino Martí Català Gianfranco Lovison Paolo Giudici Barbara Tarantino Francesco Bartolucci Giovanna Jona Lasinio Marco Mingione Alessio Farcomeni Ajitesh Srivastava Pablo Montero‐Manso Aniruddha Adiga Benjamin Hurt Bryan Lewis Madhav Marathe

Short-term forecasts of infectious disease burden can contribute to situational awareness and aid capacity planning. Based on best practice in other fields recent insights epidemiology, one maximise the predictive performance such if multiple models are combined into an ensemble. Here, we report ensembles predicting COVID-19 cases deaths across Europe between 08 March 2021 07 2022.

10.7554/elife.81916 article EN public-domain eLife 2023-04-21

The characteristics of the power-line communication (PLC) channel are difficult to model due heterogeneity networks and lack common wiring practices. To obtain full variability PLC channel, random generators great importance for design testing algorithms. In this respect, we propose a generator that is based on top-down approach. Basically, describe multipath propagation coupling effects with an analytical model. We introduce into restricted set parameters and, finally, fit measured...

10.1109/tpwrd.2012.2196714 article EN IEEE Transactions on Power Delivery 2012-06-12

10.1007/978-3-642-33415-3_5 article EN Lecture notes in computer science 2012-01-01

Energy efficiency is a major design issue in the context of Wireless Sensor Networks (WSN). If acquired data to be sent far-away base station, collaborative beamforming performed by sensors may help distribute communication load among nodes and reduce fast battery depletion. However, techniques are far from optimality many cases we might wasting more power than required. We consider energy applications. Using convex optimization framework, propose virtual beamformer that maximizes network...

10.1109/tsp.2013.2288080 article EN IEEE Transactions on Signal Processing 2013-11-19

10.1109/icassp49660.2025.10888212 article EN ICASSP 2022 - 2022 IEEE International Conference on Acoustics, Speech and Signal Processing (ICASSP) 2025-03-12

Abstract. Emissions of harmful substances into the atmosphere are a serious environmental concern. In order to understand and predict their effects, it is necessary estimate exact quantity timing emissions from sensor measurements taken at different locations. There number methods for solving this problem. However, these existing assume Gaussian additive errors, making them extremely sensitive outlier measurements. We first show that errors in real-world measurement data sets come...

10.5194/gmd-7-2303-2014 article EN cc-by Geoscientific model development 2014-10-10

Since the beginning of COVID-19 pandemic, many dashboards have emerged as useful tools to monitor its evolution, inform public, and assist governments in decision-making. Here, we present a globally applicable method, integrated daily updated dashboard that provides an estimate trend evolution number cases deaths from reported data more than 200 countries territories, well 7-d forecasts. One significant difficulties managing quickly propagating epidemic is details dynamic needed forecast are...

10.1073/pnas.2112656119 article EN cc-by-nc-nd Proceedings of the National Academy of Sciences 2022-08-03

Recent work on action recognition leverages 3D features and textual information to achieve state-of-the-art performance. However, most of the current few-shot methods still rely 2D frame-level representations, often require additional components model temporal relations, employ complex distance functions accurate alignment these representations. In addition, existing struggle effectively integrate semantics, some resorting concatenation or addition visual features, using text merely as an...

10.1109/wacv57701.2024.00633 article EN 2022 IEEE/CVF Winter Conference on Applications of Computer Vision (WACV) 2024-01-03

It often happens that we are interested in reconstructing an unknown signal from partial measurements. Also, it is typically assumed the location (temporal or spatial) of each sample known and only distortion present observations due to additive measurement noise. However, there some applications where such information lost. In this paper, consider situation which order noisy samples, taken a linear system, missing. Previous work on topic has considered noiseless case exhaustive search...

10.1109/icassp.2017.7953021 article EN 2017-03-01

We propose a random channel generator for in-home power line communications (PLC). follow statistical top-down approach and we model the multipath propagation effects of PLC in frequency domain. Then, introduce variability into model, i.e., let parameters associated to reflections be random, according certain statistics. Finally, fit experimental data. target average path loss root-mean-square (RMS) delay spread measured channels. According this methodology, show that randomly generated...

10.1109/glocom.2011.6133815 article EN 2011-12-01

Energy efficiency, scalability and robustness are key features of Ad-hoc Wireless Sensor Networks the use decentralized algorithms is practical importance in such scenarios. A method for node localization proposed by solving a nonlinear least-squares problem distributed fashion. For that purpose we propose Gauss-Newton algorithm with embedded consensus requires only local communication converges to centralized version.

10.1109/acssc.2010.5757776 article EN 2010-11-01

We address the problem of sampling and reconstruction sparse signals with finite rate innovation. derive general conditions under which perfect is possible for kernels satisfying Strang-Fix conditions. Previous results on subject consider two particular cases; when kernel able to reproduce (complex) exponentials, or it has polynomial reproduction property. In this paper, we extend such analysis case where both properties could be found in show that former situations can regarded as special...

10.1109/tsp.2018.2791973 article EN IEEE Transactions on Signal Processing 2018-01-11
Katharine Sherratt Hugo Gruson Rok Grah Hillary Johnson Rene Niehus and 95 more Bastian Prasse F. Sandman Jannik Deuschel Daniel Wolffram Sam Abbott Alexander Ullrich Graham Gibson EL. Ray NG. Reich Daniel Sheldon Yijin Wang Nutcha Wattanachit L. Wang Ján Trnka Guillaume Obozinski Tao Sun Dorina Thanou Laurence Pottier Ekaterina Krymova Maria Vittoria Barbarossa Neele Leithäuser Jan Möhring Johanna Schneider Jarosław Wlazło Jan Fuhrmann Berit Lange Isti Rodiah Prasith Baccam Heidi Gurung Steven A. Stage Brad T. Suchoski Jozef Budzinski Robert Walraven Inmaculada Villanueva Vít Tuček Martin Šmíd Milan Zajíček C. Pérez Álvarez Borja Reina Nikos I Bosse Sophie Meakin Pierfrancesco Alaimo Di Loro Antonello Maruotti Veronika Eclerová Andrea Kraus David Kraus Lenka Přibylová Babalis Dimitris ML. Li Soni Saksham Jonas Dehning Sebastian Mohr Viola Priesemann Grzegorz Redlarski Benjamı́n Béjar Giovanni Ardenghi Nicola Parolini Giovanni Ziarelli Wolfgang Böck Stefan Heyder Thomas Hotz David E Singh Miguel Guzmán-Merino Jose L Aznarte David Moriña Sergio Alonso E. Álvarez Daniel López Clara Prats JP. Burgard Arne Rodloff Thomas Zimmermann Alexander Kuhlmann Janez Žibert Fulvia Pennoni Fabio Divino Martí Català Gianfranco Lovison Paolo Giudici Barbara Tarantino Francesco Bartolucci Giovanna Jona Lasinio Marco Mingione Alessio Farcomeni Ajitesh Srivastava Pablo Montero‐Manso Aniruddha Adiga Benjamin Hurt Bryan Lewis Madhav Marathe Przemyslaw Porebski Srinivasan Venkatramanan Rafał Bartczuk Filip Dreger Anna Gambin

Abstract Background Short-term forecasts of infectious disease burden can contribute to situational awareness and aid capacity planning. Based on best practice in other fields recent insights epidemiology, one maximise the predictive performance such if multiple models are combined into an ensemble. Here we report ensembles predicting COVID-19 cases deaths across Europe between 08 March 2021 07 2022. Methods We used open-source tools develop a public European Forecast Hub. invited groups...

10.1101/2022.06.16.22276024 preprint EN cc-by medRxiv (Cold Spring Harbor Laboratory) 2022-06-16

Abstract Hybrid Pixel Detectors (HPDs) are highly suitable in diffraction-based electron microscopy due to their high frame rates (&gt; 1 kHz), dynamic range, and good radiation hardness. However, use imaging applications has been limited by relatively large pixel size (≥ 55 μm) high-energy (&gt;80 keV) electrons scattering over multiple pixels the sensor layer. To realize full potential of fast, radiation-hard HPDs across modalities, we developed deep learning techniques precisely localize...

10.1088/1748-0221/19/01/c01020 article EN cc-by Journal of Instrumentation 2024-01-01

Mismatches between samples and their respective channel or target commonly arise in several real-world applications. For instance, whole-brain calcium imaging of freely moving organisms, multiple-target tracking multi-person contactless vital sign monitoring may be severely affected by mismatched sample-channel assignments. To address this issue systematically, we frame it as a signal reconstruction problem where correspondences channels are lost. Assuming sensing matrix for the signals,...

10.1016/j.sigpro.2024.109579 article EN cc-by-nc Signal Processing 2024-06-13

Recently, a new ICT paradigm emerged, which considers Multiple Devices that cooperate in Tasks (MDMT). Under this paradigm, cooperation among the nodes can be beneficial when subsets of share common interests or observations. For to successful, it is thus necessary account for decentralized labelling scheme allows uniquely identify every object interest. Such not only ensures proper data exchange but also formation interest-specific clusters and hence, might from communications cost...

10.1109/afrcon.2015.7331863 article EN AFRICON 2015-09-01

Positioning in Wireless Sensor Networks is a key feature many applications. Finding efficient algorithms to perform this task of practical importance systems where limitations on the computational power and battery life are major issue. Forming coalitions within set visible nodes target can help reduce communication costs. We then formulate problem as coalitional game cooperation does not come for free.

10.5281/zenodo.41935 article EN European Signal Processing Conference 2010-08-23

Wireless sensor networks are posed as the new communication paradigm where use of small, low-complexity, and low-power devices is preferred over costly centralized systems. The spectra potential applications very wide, ranging from monitoring, surveillance, localization, among others. Localization a key application in simple, efficient, distributed algorithms paramount practical importance. Combining convex optimization tools with consensus we propose localization algorithm for scenarios...

10.1186/1687-6180-2012-95 article EN cc-by EURASIP Journal on Advances in Signal Processing 2012-05-01

Traditional sampling results assume that the sample locations are known. Motivated by simultaneous localization and mapping (SLAM) structure from motion (SfM), we investigate at unknown locations. Without further constraints, problem is often hopeless. For example, recently showed that, for polynomial bandlimited signals, it possible to find two arbitrarily far each other, fit measurements. However, also this can be overcome adding constraints positions. In paper, show these lead a uniform...

10.1109/tsp.2018.2872019 article EN IEEE Transactions on Signal Processing 2018-09-24
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